Update phpstan/phpstan requirement from 2.1.0 to 2.1.6

Updates the requirements on [phpstan/phpstan](https://github.com/phpstan/phpstan) to permit the latest version.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Changelog](https://github.com/phpstan/phpstan/blob/2.1.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@2.1.0...2.1.6)

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

composer.json

@@ -8,7 +8,7 @@
         "php-64bit": "*"
     },
     "require-dev": {
-        "phpstan/phpstan": "2.1.0",
+        "phpstan/phpstan": "2.1.6",
         "phpstan/extension-installer": "^1.0",
         "phpstan/phpstan-strict-rules": "^2.0",
         "phpunit/phpunit": "^10.0 || ^11.0"